FIG. 17 is a block diagram of conventional receiver 101 disclosed in Patent Literature 1. As shown in FIG. 17, receiver 101 includes oscillators 102A and 102B, frequency converter 103, filter 104 connected to an output of frequency converter 103, AD converter 105, band-pass filters 110 and 111 connected to an output of AD converter 105, and demodulators 120 connected to respective outputs of band-pass filters 110 and 111. Oscillators 102A and 102B generate local oscillator signals. Frequency converter 103 heterodynes received signals of one or more channels into intermediate frequency (IF) signals with using the local oscillator signals generated by oscillators 102A and 102B. AD converter 105 converts analog signals received from filter 104 into digital signals.
Conventional receiver 101 can receive signals of plural channels simultaneously due to a single frequency converter 103 perform the heterodyning using plural oscillators 102A and 102B.
Conventional receiver 101, however, concurrently uses plural oscillators 102A and 102B in order to concurrently receive plural signals, thus requiring a large circuit size and a large electric power consumption.    Patent Literature 1: JP2004-357025A